Module for high-and medium-voltage eletric station

ABSTRACT

A module for a high- and medium-voltage electric station, comprising: a supporting frame, which has a fixed part and a movable part; first actuation means, which are suitable to move said movable part; first and second sets of three insulating posts, arranged on the fixed part along two corresponding rows; first and second disconnection contacts being respectively associated with the insulating posts of the first and second sets and being electrically connectable, in input and in output with respect to the module, to corresponding electric terminals. The particularity of the modules consists of the fact that it comprises a set of three multifunctional interruption assemblies, each of which comprises:  
     a supporting insulator, arranged on the movable part and connected in an elbow-shaped configuration to a containment insulator which contains at least one interruption unit which has a fixed contact and a movable contact which is operatively connected to second actuation means;  
     third and fourth disconnection contacts, which are electrically connected to the interruption unit and are connected, in a disconnectable way, to the first and second disconnection contacts, respectively; the actuation of the movable part producing a movement of the multifunctional assemblies between a first position, in which the third and fourth disconnection contacts are respectively connected to the corresponding first and second disconnection contacts, and a second position, in which they are disconnected therefrom. Further, the first and/or second actuation means comprise a motor with position control.

[0001] The present invention relates to a module for a high- andmedium-voltage electric station, i.e. for applications with operatingvoltages above 1000V; more particularly, the present invention relatesto a module for an electric station which distinguishes itself withrespect to known types of device due to the simplicity, compactness andmodularity of its constructive structure and is accordingly extremelyflexible in application and significantly convenient from an economicpoint of view.

[0002] It is known from the art that air-insulated high- andmedium-voltage electric stations use a system of busbars, each of whichis appropriately connected to a main electric power supply line and to apower transformer; the substation is furthermore provided with a seriesof primary components, for example disconnectors, circuit breakers,instrument transformers, et cetera, and secondary components, such asbusbar protections, maximum-current protections, and control systems.

[0003] According to a conventional embodiment, the stations are producedby assembling the various components directly on site, generallyarranging them on mutually separate supports. This solution entails aconsiderable use of labor at the installation site for assembly,adjustment and electrical testing. This solution furthermore entails theuse of considerable space, which leads to an increase in the costsrequired for the purchase of land and, in view of the large number offoundations and supports required, to an increase in constructiondifficulties, especially when the space available is limited and/or thepreparation of the foundations is rendered difficult by the very natureof the soil; furthermore, the environmental impact is considerablynegative. If one wishes to avoid performing electrical testing at theinstallation site, it is necessary to oversize the insulation distancesfor safety reasons and therefore oversize accordingly the entirestation.

[0004] Constructive solutions are also known which use apparatuses whichintegrate multiple electrical functions in a single component. Anexample of this type is described in European patent application no.0774814. Another known type of solution associates with eachinterruption pole a two-blade disconnector and performs thedisconnection maneuvers by turning said pole; conventional instrumenttransformers can furthermore be optionally integrated in the structureof the pole. Although these solutions adequately achieve the requiredelectrical performance and allow a reduction of the required supportswith respect to more conventional solutions, they still require assemblydirectly at the installation site, with the same drawbacks noted above.Furthermore, the interruption poles are generally constituted byshaft-like insulators which are constituted by two parts: a first one,commonly known as supporting insulator, inside which the means foractuating the contacts of the circuit breaker are arranged, and a secondone, which is arranged in the upper part of the pole and contains theinterruption elements. Accordingly, visual impact is still considerable,also in view of the fact that the constructive dimensions increase asthe voltage involved increases; any use of conventional instrumenttransformers inside the pole contributes to an increase in spaceoccupation and visual impact.

[0005] Another considerable drawback of known types of solution is thefact that the electrical maneuvers are generally performed by means ofmechanical actuation devices which have a large number of components andrequire long and complicated adjustments; furthermore, the movement ofthe moving parts, particularly of the movable contacts, cannot bechanged by the user but is set during design. This lack of controlfurthermore requires the presence of damping elements or shock absorbersin order to dissipate the residual kinetic energy at the end of themaneuver and avoid uncontrolled impacts. Furthermore, due to the largenumber of components, frequent maintenance interventions are required inorder to maintain nominal behavior and therefore ensure repeatability ofmaneuvers.

[0006] Alternatively, actuation devices of the hydraulic type are usedwhich can partly obviate these drawbacks but have inherent limitationslinked to the presence of fluids, especially as a consequence of theirtemperature-sensitivity.

[0007] The aim of the present invention is to provide a module for ahigh- and medium-voltage electric station whose structure allows toperform assembly and technical testing directly at the factory, thusallowing transport to the site in a configuration which is alreadypreset for the operative placement.

[0008] Within the scope of this aim, an object of the present inventionis to provide a module for a high- and medium-voltage electric stationwhich has a multifunctional structure in which electrical maneuvers canbe performed simply and effectively, allowing accuracy and repeatabilityof said maneuvers, and a significant reduction in the space requiredwith respect to the state of the art.

[0009] Another object of the present invention is to provide a modulefor a high- and medium-voltage electric station which has a compact andmodular structure which allows to reduce environmental visual impact andinstallation costs.

[0010] A further object of the present invention is to provide a modulefor a high- and medium-voltage electric station which is highlyreliable, relatively easy to manufacture and at competitive costs.

[0011] This aim, these objects and others which will become apparenthereinafter are achieved by a module for a high- and medium-voltageelectric station, comprising: a supporting frame, which has a fixed partand a movable part; first actuation means, which are suitable to movesaid movable part; a first and a second sets of three insulating posts,arranged on the fixed part along two corresponding rows; first andsecond disconnection contacts being respectively associated with theinsulating posts of said first and second sets and being electricallyconnectable, in input and in output with respect to the module, tocorresponding electric terminals; characterized in that it comprises aset of three multifunctional interruption assemblies, each of whichcomprises:

[0012] a supporting insulator, arranged on said movable part andconnected in an elbow-shaped configuration to a containment insulator,said containment insulator containing at least one interruption unitwhich has a fixed contact and a movable contact which is operativelyconnected to second actuation means;

[0013] third and fourth disconnection contacts, which are electricallyconnected to said interruption unit and are connected, in adisconnectable way, to said first and second disconnection contacts,respectively; the actuation of said movable part producing a movement ofthe multifunctional assemblies between a first position, in which thethird and fourth disconnection contacts are respectively connected tothe corresponding first and second disconnection contacts, and a secondposition, in which they are disconnected therefrom; and in that saidfirst and/or second actuation means comprise a motor with positioncontrol.

[0014] In this manner, one obtains an extremely compact module in whichelectrical maneuvers are performed very simply and effectively, at thesame time ensuring their accuracy and repeatability. Furthermore, themodule according to the invention has a constructive structure whichmakes it directly transportable to the installation site in an alreadypreassembled configuration, with an installation and supporting framelayout which considerably reduces the space required and at the sametime reduces the number of foundations and supports required and alsoreduces environmental impact.

[0015] Further characteristics and advantages of the invention willbecome apparent from the description of preferred but not exclusiveembodiments of the module according to the invention, illustrated onlyby way of non-limitative example in the accompanying drawings, wherein:

[0016]FIG. 1 is a perspective view of the module for a high- andmedium-voltage electric station according to the invention;

[0017]FIG. 2 is a detailed perspective view of a part of the module ofFIG. 1;

[0018]FIG. 3 is a top view of the module according to the invention in adisconnection position;

[0019]FIG. 4 is a perspective view of the movable part of the moduleaccording to the invention, shown separated from the fixed part.

[0020] With reference to the above cited figures, the module for a high-and medium-voltage electric station according to the invention,generally designated by the reference numeral 100, comprises asupporting frame which has a fixed part 1 and a movable part 2 withwhich first actuation means are associated, the first actuation meansbeing suitable to move said movable part 2. Advantageously, the firstactuation means comprise a kinematic chain and a motor with positioncontrol 3, preferably a rotary servomotor, for the purposes detailedhereinafter.

[0021] A first set 4 and a second set 5 of three insulating posts arearranged on the fixed part 1 of the frame and are aligned along twocorresponding rows; first disconnection contacts 6 and seconddisconnection contacts 7 are respectively associated with eachinsulating post 4 and with each insulating post 5 and can beelectrically connected, in input and in output with respect to themodule, to corresponding electrical terminals, not shown. Saiddisconnection contacts 6 and 7, for example of the clamp type, can berespectively connected to the phases of an electric power supply lineand to busbars; numerous alternative connection configurations can beeasily provided in practice.

[0022] The module 100 furthermore has a set of three multifunctionalinterruption assemblies, designated by the reference numeral 10, each ofwhich comprises a supporting insulator 8, which is arrangedsubstantially vertically on the movable part 2 and is transverselyconnected, in an elbow-shaped configuration, to a containment insulator9. Advantageously, each supporting insulator 8 is connected to thecorresponding containment insulator 9 by interposing a single metalliccollar 13; alternatively, it is possible to use multiple intermediatecomponents, according to conventional solutions which are widely knownin the art.

[0023] Inside each containment insulator 9 there is at least oneinterruption unit, i.e. a high-voltage circuit breaker, which comprisesan interruption chamber arranged substantially horizontal, a dielectricfluid, for example SF₆, a fixed contact and a movable contact, accordingto embodiments which are widely known in the art and accordingly are notillustrated. The movable contact is operatively connected to secondactuation means.

[0024] Each multifunctional assembly 10 furthermore comprises thirddisconnection contacts 14 and fourth disconnection contacts 15, forexample of the blade type, which are electrically connected to theinterruption unit and are connected, in a separable way, respectively tothe first disconnection contacts 6 and to the second disconnectioncontacts 7. In practice, the movement of the movable part 2 determines amovement of the multifunctional assemblies 10 between a first position,in which the third disconnection contacts 14 and the fourthdisconnection contacts 15 are respectively connected to thecorresponding first disconnection contacts 6 and to the seconddisconnection contacts 7, and a second position, shown in FIG. 3, inwhich they are disconnected from them.

[0025] Advantageously, the movement of the movable part 2 occurs bymeans of the servomotor 3 and the use of a worm screw 12 which issuitable to convert the rotary motion of the shaft of the servomotor 3into a translation movement of said movable part 2. For example, themovable part can be provided with wheels which slide in rails providedin the fixed part 1.

[0026] In this way, the disconnection maneuvers occur in a functionallyeffective manner and according to a simple constructive solution whichallows to reduce the components required and the corresponding spaceoccupations.

[0027] Advantageously, the second actuation means also comprise a motorwith position control 11, preferably a rotary servomotor. In this case,the servomotor is connected to the movable contact of the interruptionunit by virtue of a kinematic chain which is suitable to convert therotary motion of the servomotor shaft into a translation movement of themovable contact; embodiments of said kinematic chains are widely knownin the art and accordingly are not described in detail.

[0028] In particular, according to a preferred embodiment, the module100 can comprise a single motor 11 connected to the movable contacts ofthe three interruption units, for example by means of a connecting rod16, as shown in FIGS. 1 to 4; alternatively, it is possible to use threedifferent motors 11, each of which is connected to a correspondinginterruption unit.

[0029] Furthermore, according to an embodiment which is not shown, it ispossible to use a single motor with position control, operativelyconnected to the movable contacts of the interruption units and to themovable part 2; in this manner, with a single motor it is possible toperform both interruption and disconnection maneuvers, according to asolution which allows to further reduce the components used andaccordingly reduce costs and space occupation.

[0030] The use of a motor with position control, and particularly of arotary servomotor, allows to ensure accuracy and repeatability of theinterruption and disconnection maneuvers, with a constructive solutionwhich is simplified with respect to the actuation means of the knownart; accordingly, the dimensions are also reduced. The use of aservomotor allows to have considerable power levels available with shortdelivery times.

[0031] Position control can be performed, both for the motor 3 and forthe motor 11, by means of a position sensor located on the motor, whichsends to a control unit information related to the movement of saidmotor. Position control, particularly for the interruption maneuvers,can also be performed by a movable contact position sensor which sendsto the control unit information related to the actual position of themovable contact. Said position sensor can be simply a stroke limitdevice which signals to the control unit that the requested maneuver hasbeen completed.

[0032] By means of the control unit it is in fact possible, for example,to program in a simple and flexible manner the rule of motion of themoving parts according to the actuation and to the type of faultpossibly detected. In particular, it is possible to predefine thepositioning precision of the movable contact of the interruption unitsboth for opening and for closure, reducing the risks of damage currentlylinked to overrun problems.

[0033] The module 100 furthermore comprises instrument transformers, notshown. In particular, according to a preferred embodiment, the module100 comprises optical current sensors, each arranged inside acorresponding interruption unit. Preferably, the optical current sensorsare arranged inside the volume of the interruption unit occupied by thedielectric fluid, for example in the interruption chamber, morepreferably proximate to the fixed contact or movable contact.

[0034] Possible embodiments of said optical sensors are described indetail in International patent application no. PCT/EP99/05750, thedescription of which is assumed included herein by reference.

[0035] The use of an optical current sensor allows to accurately measurethe current that flows in each pole, avoiding the non-ideal conditionsthat are typical of conventional magnetic-core current transformers.Furthermore, placement inside the volume occupied by the dielectricfluid, and particularly in the interruption chamber, allows toconsiderably reduce space occupation and facilitate placementoperations, especially when the sensor is located proximate to thecontacts.

[0036] Another advantage is provided by the fact that at least insideone set of three insulating posts, for example in the insulating posts5, it is possible to use voltage transformers, preferably constituted byoptical voltage sensors; in this manner, the module also integrates afunction for measuring the voltage involved, according to a solutionwhich occupies substantially no space, since the sensor is arrangedinside the insulating posts.

[0037] Another advantage of the module 100 according to the invention isthe fact that the assembly constituted by the movable part 2 and theinterruption units 10 can be moved both substantially horizontally, asdescribed earlier for the execution of the disconnection maneuvers, andsubstantially vertically, as shown schematically in FIG. 4, with respectto the fixed part 1. In this manner, for example, the execution of anymaintenance is facilitated; furthermore, the movable part of the moduleconstitutes a core which can be easily removed from the fixed part incase of total or partial replacement of components.

[0038] Another advantage is provided by the fact that the insulatingposts 4 and 5, the supporting insulators 8 and the containmentinsulators 9 have a substantially tubular body made of polymericmaterial, around which silicone rubber fins are arranged. This solutionprovides an overall weight reduction of the module with respect to theuse of conventional insulators, for example ceramic ones, and improvesdielectric strength, particularly in polluted working environments.Furthermore, the insulating posts of at least one of the two sets ofthree can be provided so as to comprise surge arresters.

[0039] The module 100 according to the invention is particularlysuitable to be used in the realization of high- and medium-voltageelectric substations. Accordingly, the present invention also relates toa high- and medium-voltage electric substation, characterized in that itcomprises a module according to the present invention.

[0040] In practice it has been found that the module according to theinvention fully achieves the intended aim, since it has a simple andcompact structure, in which the electrical maneuvers are performedextremely simply and effectively, at the same time ensuring theiraccuracy and repeatability. Furthermore, the module has a constructivestructure which makes it directly transportable to the installation sitein an already preassembled configuration, with an installation andsupporting frame layout which considerably reduces the space required,at the same reducing the number of foundations and supports required andthe corresponding environmental impact. Particularly by virtue of itseasy transportability, the module 100 is particularly suitable for theprovision of mobile high- and medium-voltage electric substations.

[0041] The module thus conceived is susceptible of numerousmodifications and variations, all of which are within the scope of theinventive concept; all the details may furthermore be replaced withother technically equivalent elements. In practice, the materials used,so long as they are compatible with the specific use, as well as thedimensions, may be any according to the requirements and the state ofthe art.

1. A module for a high- and medium-voltage electric station, comprising:a supporting frame, which has a fixed part and a movable part; firstactuation means, which are suitable to move said movable part; a firstand a second sets of three insulating posts, arranged on the fixed partalong two corresponding rows; first and second disconnection contactsbeing respectively associated with the insulating posts of said firstand second sets and being electrically connectable, in input and inoutput with respect to the module, to corresponding electric terminals;characterized in that it comprises a set of three multifunctionalinterruption assemblies, each of which comprises: a supportinginsulator, arranged on said movable part and connected in anelbow-shaped configuration to a containment insulator, said containmentinsulator containing at least one interruption unit which has a fixedcontact and a movable contact which is operatively connected to secondactuation means; third and fourth disconnection contacts, which areelectrically connected to said interruption unit and are connected, in adisconnectable way, to said first and second disconnection contacts,respectively; the actuation of said movable part producing a movement ofthe multifunctional assemblies between a first position, in which thethird and fourth disconnection contacts are respectively connected tothe corresponding first and second disconnection contacts, and a secondposition, in which they are disconnected therefrom; and in that saidfirst and/or second actuation means comprise a motor with positioncontrol.
 2. The module for a high- and medium-voltage electric stationaccording to claim 1, characterized in that said first actuation meanscomprise a kinematic chain and a rotary servomotor.
 3. The module for ahigh- and medium-voltage electric station according to claim 2,characterized in that said kinematic chain comprises a worm screw whichis suitable to convert the rotary motion of the shaft of the servomotorinto a translating movement of said movable part of the supportingframe.
 4. The module for a high- and medium-voltage electric stationaccording to claim 1, characterized in that said second actuation meanscomprise a kinematic chain and a rotary servomotor.
 5. The module for ahigh- and medium-voltage electric station according to claim 4,characterized in that said second actuation means comprise a singlerotary servomotor which is operatively connected to the movable contactsof the interruption units.
 6. The module for a high- and medium-voltageelectric station according to claim 4, characterized in that said secondactuation means comprise a set of three rotary servomotors, each ofwhich is operatively connected to the movable contact of thecorresponding interruption unit.
 7. The module for a high- andmedium-voltage electric station according to claim 1, characterized inthat instrument transformers are arranged inside said interruptionassemblies.
 8. The module for a high- and medium-voltage electricstation according to claim 7, characterized in that said instrumenttransformers comprise an optical current sensor which is arranged insidesaid interruption unit.
 9. The module for a high- and medium-voltageelectric station according to claim 8, characterized in that saidoptical current sensor is arranged inside a volume of the interruptionunit which is occupied by a dielectric fluid.
 10. The module for a high-and medium-voltage electric station according to claim 9, characterizedin that said optical current sensor is arranged inside the interruptionchamber proximate to one of the contacts.
 11. The module for a high- andmedium-voltage electric station according to one or more of thepreceding claims, characterized in that at least one optical voltagesensor is arranged inside a set of three insulating posts.
 12. Themodule for a high- and medium-voltage electric station according to oneor more of the preceding claims, characterized in that the assemblyconstituted by the movable part and the interruption assemblies can moveboth substantially horizontally and substantially vertically.
 13. Themodule for a high- and medium-voltage electric station according to oneor more of the preceding claims, characterized in that the supportinginsulators are connected to the corresponding containment insulators bymeans of a single metallic collar, said supporting insulators and saidcontainment insulators comprising a substantially tubular body made ofpolymeric material, around which silicone rubber fins are arranged. 14.The module for a high- and medium-voltage electric station according toone or more of the preceding claims, characterized in that said firstand second sets of three insulating posts comprise a substantiallytubular body made of polymeric material, around which silicone rubberfins are arranged, at least one of said first and second sets of threeinsulating posts comprising a surge arrester.
 15. A high- andmedium-voltage electrical substation, characterized in that it comprisesa module according to one or more of the preceding claims.
 16. A high-and medium-voltage mobile electrical substation, characterized in thatit comprises a module according to one or more of claims 1 to 14.